S
M
T
W
T
F
S
26
51°
39°
27
58°
43°
28
45°
35°
29
63°
32°
30
62°
37°
1
64°
37°
2
72°
31°
3
78°
46°
4
82°
46°
5
51°
44°
6
57°
40°
7
77°
38°
8
79°
46°
9
74°
47°
10
74°
42°
11
85°
51°
12
82°
56°
13
82°
45°
14
87°
60°
15
95°
52°
16
89°
54°
17
81°
54°
18
62°
41°
19
68°
46°
20
66°
50°
21
63°
50°
22
72°
49°
23
78°
55°
24
80°
58°
25
89°
61°
26
84°
60°
27
83°
59°
28
87°
60°
29
84°
58°
30
84°
60°
31
82°
56°
1
83°
60°
2
83°
59°
3
77°
56°
4
80°
61°
5
85°
62°
6
87°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Gretna
Gretna's May 2026 forecast shows daily high temperatures ranging from 62° to 89°, with overnight lows between 41° and 62°. The average high for May is 79° with an average low of 56°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Gretna. See also: June | July | August.